No, Sir Francis Drake and Sir Walter Raleigh were not related by blood. Although both were prominent figures in the Elizabethan era, they came from different backgrounds and families.
Sir Francis Drake was born in Devon, England, around 1540 and is best known for being an explorer, sea captain, and privateer. He was the first Englishman to circumnavigate the globe and played a significant role in the defeat of the Spanish Armada in 1588.
On the other hand, Sir Walter Raleigh was born in 1552 in Devon, England as well. He was an explorer, writer, and soldier, and is often credited with popularizing tobacco in England and attempting to establish a colony in Virginia. He was a favorite of Queen Elizabeth I, which afforded him some considerable power and influence.
While both men made significant contributions to English exploration and history, their paths did not cross in a familial sense. They did, however, have different relationships with the crown and with the Spanish, which sometimes put them at odds with one another as they navigated the politics of the time.